They are so small, because besides the always on DRM, it is also asking the servers for math constantly in the glassbox engine. You're half playing on your computer, half on the "cloud" as well as it were. And no these aren't the size of a SC4 "medium" city. They are the size of a SC2000 city.

It is still an amazing simulation with lots of fun things to look at, but the scope shifted from large city to region play, region play with other people. Still not sure how that is gonna work out.